<template>
    <div :class="cx('root')" v-bind="ptmi('root')">
        <template v-if="loading && loadingMode === 'mask'">
            <div :class="cx('loadingOverlay')" v-bind="ptm('loadingOverlay')">
                <slot name="loadingicon" :class="cx('loadingIcon')">
                    <i v-if="loadingIcon" :class="[cx('loadingIcon'), 'pi-spin', loadingIcon]" v-bind="ptm('loadingIcon')" />
                    <SpinnerIcon v-else spin :class="cx('loadingIcon')" v-bind="ptm('loadingIcon')" />
                </slot>
            </div>
        </template>
        <div v-if="filter" :class="cx('filterContainer')" v-bind="ptm('filterContainer')">
            <input v-model="filterValue" type="text" autocomplete="off" :class="cx('input')" :placeholder="filterPlaceholder" @keydown="onFilterKeydown" v-bind="ptm('input')" />
            <slot name="searchicon" :class="cx('searchIcon')">
                <SearchIcon :class="cx('searchIcon')" v-bind="ptm('searchIcon')" />
            </slot>
        </div>
        <div :class="cx('wrapper')" :style="{ maxHeight: scrollHeight }" v-bind="ptm('wrapper')">
            <ul :class="cx('container')" role="tree" :aria-labelledby="ariaLabelledby" :aria-label="ariaLabel" v-bind="ptm('container')">
                <TreeNode
                    v-for="(node, index) of valueToRender"
                    :key="node.key"
                    :node="node"
                    :templates="$slots"
                    :level="level + 1"
                    :index="index"
                    :expandedKeys="d_expandedKeys"
                    @node-toggle="onNodeToggle"
                    @node-click="onNodeClick"
                    :selectionMode="selectionMode"
                    :selectionKeys="selectionKeys"
                    @checkbox-change="onCheckboxChange"
                    :loadingMode="loadingMode"
                    :unstyled="unstyled"
                    :pt="pt"
                ></TreeNode>
            </ul>
        </div>
    </div>
</template>

<script>
import SearchIcon from 'primevue/icons/search';
import SpinnerIcon from 'primevue/icons/spinner';
import { ObjectUtils } from 'primevue/utils';
import BaseTree from './BaseTree.vue';
import TreeNode from './TreeNode.vue';

export default {
    name: 'Tree',
    extends: BaseTree,
    inheritAttrs: false,
    emits: ['node-expand', 'node-collapse', 'update:expandedKeys', 'update:selectionKeys', 'node-select', 'node-unselect', 'filter'],
    data() {
        return {
            d_expandedKeys: this.expandedKeys || {},
            filterValue: null
        };
    },
    watch: {
        expandedKeys(newValue) {
            this.d_expandedKeys = newValue;
        }
    },
    methods: {
        onNodeToggle(node) {
            const key = node.key;

            if (this.d_expandedKeys[key]) {
                delete this.d_expandedKeys[key];
                this.$emit('node-collapse', node);
            } else {
                this.d_expandedKeys[key] = true;
                this.$emit('node-expand', node);
            }

            this.d_expandedKeys = { ...this.d_expandedKeys };
            this.$emit('update:expandedKeys', this.d_expandedKeys);
        },
        onNodeClick(event) {
            if (this.selectionMode != null && event.node.selectable !== false) {
                const metaSelection = event.nodeTouched ? false : this.metaKeySelection;
                const _selectionKeys = metaSelection ? this.handleSelectionWithMetaKey(event) : this.handleSelectionWithoutMetaKey(event);

                this.$emit('update:selectionKeys', _selectionKeys);
            }
        },
        onCheckboxChange(event) {
            this.$emit('update:selectionKeys', event.selectionKeys);

            if (event.check) this.$emit('node-select', event.node);
            else this.$emit('node-unselect', event.node);
        },
        handleSelectionWithMetaKey(event) {
            const originalEvent = event.originalEvent;
            const node = event.node;
            const metaKey = originalEvent.metaKey || originalEvent.ctrlKey;
            const selected = this.isNodeSelected(node);
            let _selectionKeys;

            if (selected && metaKey) {
                if (this.isSingleSelectionMode()) {
                    _selectionKeys = {};
                } else {
                    _selectionKeys = { ...this.selectionKeys };
                    delete _selectionKeys[node.key];
                }

                this.$emit('node-unselect', node);
            } else {
                if (this.isSingleSelectionMode()) {
                    _selectionKeys = {};
                } else if (this.isMultipleSelectionMode()) {
                    _selectionKeys = !metaKey ? {} : this.selectionKeys ? { ...this.selectionKeys } : {};
                }

                _selectionKeys[node.key] = true;
                this.$emit('node-select', node);
            }

            return _selectionKeys;
        },
        handleSelectionWithoutMetaKey(event) {
            const node = event.node;
            const selected = this.isNodeSelected(node);
            let _selectionKeys;

            if (this.isSingleSelectionMode()) {
                if (selected) {
                    _selectionKeys = {};
                    this.$emit('node-unselect', node);
                } else {
                    _selectionKeys = {};
                    _selectionKeys[node.key] = true;
                    this.$emit('node-select', node);
                }
            } else {
                if (selected) {
                    _selectionKeys = { ...this.selectionKeys };
                    delete _selectionKeys[node.key];

                    this.$emit('node-unselect', node);
                } else {
                    _selectionKeys = this.selectionKeys ? { ...this.selectionKeys } : {};
                    _selectionKeys[node.key] = true;

                    this.$emit('node-select', node);
                }
            }

            return _selectionKeys;
        },
        isSingleSelectionMode() {
            return this.selectionMode === 'single';
        },
        isMultipleSelectionMode() {
            return this.selectionMode === 'multiple';
        },
        isNodeSelected(node) {
            return this.selectionMode && this.selectionKeys ? this.selectionKeys[node.key] === true : false;
        },
        isChecked(node) {
            return this.selectionKeys ? this.selectionKeys[node.key] && this.selectionKeys[node.key].checked : false;
        },
        isNodeLeaf(node) {
            return node.leaf === false ? false : !(node.children && node.children.length);
        },
        onFilterKeydown(event) {
            if (event.code === 'Enter' || event.code === 'NumpadEnter') {
                event.preventDefault();
            }

            this.$emit('filter', { originalEvent: event, value: event.target.value });
        },
        findFilteredNodes(node, paramsWithoutNode) {
            if (node) {
                let matched = false;

                if (node.children) {
                    let childNodes = [...node.children];

                    node.children = [];

                    for (let childNode of childNodes) {
                        let copyChildNode = { ...childNode };

                        if (this.isFilterMatched(copyChildNode, paramsWithoutNode)) {
                            matched = true;
                            node.children.push(copyChildNode);
                        }
                    }
                }

                if (matched) {
                    return true;
                }
            }
        },
        isFilterMatched(node, { searchFields, filterText, strict }) {
            let matched = false;

            for (let field of searchFields) {
                let fieldValue = String(ObjectUtils.resolveFieldData(node, field)).toLocaleLowerCase(this.filterLocale);

                if (fieldValue.indexOf(filterText) > -1) {
                    matched = true;
                }
            }

            if (!matched || (strict && !this.isNodeLeaf(node))) {
                matched = this.findFilteredNodes(node, { searchFields, filterText, strict }) || matched;
            }

            return matched;
        }
    },
    computed: {
        filteredValue() {
            let filteredNodes = [];
            const searchFields = this.filterBy.split(',');
            const filterText = this.filterValue.trim().toLocaleLowerCase(this.filterLocale);
            const strict = this.filterMode === 'strict';

            for (let node of this.value) {
                let _node = { ...node };
                let paramsWithoutNode = { searchFields, filterText, strict };

                if (
                    (strict && (this.findFilteredNodes(_node, paramsWithoutNode) || this.isFilterMatched(_node, paramsWithoutNode))) ||
                    (!strict && (this.isFilterMatched(_node, paramsWithoutNode) || this.findFilteredNodes(_node, paramsWithoutNode)))
                ) {
                    filteredNodes.push(_node);
                }
            }

            return filteredNodes;
        },
        valueToRender() {
            if (this.filterValue && this.filterValue.trim().length > 0) return this.filteredValue;
            else return this.value;
        }
    },
    components: {
        TreeNode: TreeNode,
        SearchIcon: SearchIcon,
        SpinnerIcon: SpinnerIcon
    }
};
</script>
